[unreadable] [unreadable] The goal of this project is to develop a GPS-enabled multi-analyte sensor that can detect and measure exposure to trace gases present in air, specifically ozone, carbon monoxide and carbon dioxide gases. This sensor is based on the innovative exploitation of the anchoring of liquid crystals to a surface functionalized with metal ions. In preliminary studies we have demonstrated the ability to identify combinations of metals that selectively bind ozone and to design multi-arrays of metals that create fingerprints specific for functional groups. We also demonstrated the use of this new technology to rapidly (~ 10 seconds) measure exposure to ppb concentrations of an organophosphate compound. The sensing surfaces we created could be tuned to be reversible, were unaffected by humidity, and responded in a dose-dependent manner. These data strongly support the feasibility of PlatypusTM technology as the basis of a compact, multi-analyte, field deployable personal device for detection of exposure to trace gases. In this proposal we will develop a sensor subsystem and integrate it with GPS-enabled components that track and store information such as degree of exposure, time and duration of exposure and exact location of exposure events. Our intended product will allow simple uploading of the data to a computer and will be tested under field conditions. Such a product is needed to facilitate the understanding of human susceptibility to environmental exposures. [unreadable] [unreadable] [unreadable] [unreadable]